Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

FirephoxRising writes "A research pilot plant in Newcastle will trial world-first technology that turns carbon emissions into bricks and pavers for the construction industry. More efficient and stable than storing gas in the ground, the new method will sequester carbon and can work anywhere, unlike geo-sequestration which is site specific."

Perhaps they should bring them to Canberra. With the amount of CO2 emissions released there, especially now during election time, with the carbon offsets alone we could single handedly solve China's energy crisis with coal fired power plants. Combined with the close proximity to government grants, surely this will be a resounding financial success!

Politicians will be out and about spending their travel and election allowances.. not staying in Canberra.. Even the ones whose electrons are in Canberra will be looking for reasons to go elsewhere, I'm sure they will justify them as friendship visits, or what not.

OP here. It's not, of course, coal, else it would be used for fuel. It's some flavor of carbonate.

It takes all the energy initially extracted by burning the coal in the first place to convert the CO back into coal, whereas making nice stable carbonates is (depending on the metal's original form, of course) likely exothermic.

OK, OP here... Can anyone explain why I got modded "insightful"? I was going for funny, as it's obviously not coal or graphite (which would be reused as fuel, not used as pavers) but some sort of carbonate (as other posters have since pointed out.

Yes, I'm familiar with the use of +1 Insightful because +1 Funny doesn't add karma, but I'm an AC -- I don't get karma either way. Please tell me people didn't take my joke seriously and believe this was about coal...

A good question, though I'm less cynical about the presumed answer. They did say something like they were recreating the Earth's natural processes, so probably something like calcium carbonate (CaCO3), the stuff that egg and seashells are made of.

Can anybody say how various carbonates compares energetically to oil and CO2? My chemistry is pretty rusty. Since the final cycle would be oil -> CO2 -> carbonate the maximum net energy would be that from a hypothetical fossil fuel -> carbonate transition, which would tell us how energetically feasible this is with the right catalysts. If it's an endothermic reaction this is a complete non-starter except as part of some hypothetical future atmosphere-scrubber (and I do really hope we have the tech ready if it comes to that).

If the reaction is exothermic though then there's hope, especially if it's a significant portion of the (presumably larger) oil -> CO2 energetic gap. If we could complete the fossil fuel -> brick transition while generating even half as much power as currently then this could be a real game-changer. Every coal- or oil-fired power plant could have it's adjacent brick factory and become carbon neutral. We could stay on fossil fuels for centuries without aggravating the global climate, even as oil and gas run out - we have truly massive coal reserves to fall back on. Of course we'd need to really shift the attention back to general environmental protection again, and get serious about that, otherwise the search for fuel could get *really* ugly. Coal mining isn't exactly environmentally friendly

Oh, no argument that going to thorium, solar, etc. would be preferable. We're not faced with a technological problem though, but a business one. If we could profitably eliminate CO2 emissions from fossil fuels we could buy ourselves another 50-100 years for the conversion, allowing the alternative tech to become more viable for the developing nations where the current cost premium is a stumbling block.

But yeah, we're reaching the point that available fossil fuels are getting increasingly environmentally d

Actually the 100,000 year archiving for uranium waste is due to nothing but stupidity - the high level "waste" is a mixture of perfectly good uranium fuel and all the same sort of short-lived radioactive fission products that thorium would produce. Any decent reprocessing plant could separate it into fresh fuel and mid-level waste that could be much more reasonably stored. Hell, we even had nuclear reprocessing plants in the early days, but then technological advances made mining fresh uranium considera

It's been a while since I did chemistry, but calcium carbonate can be made from calcium oxide and carbon dioxide in the presence of water. I think that's more or less how it's done in sea creatures. So you've got:

CaO + H2O + CO2 --> CaCO3 + H2O

I believe the reaction takes place spontaneously when you dissolve calcium oxide and CO2 in water. To check, add up the standard enthalpy of formation for both sides. The water cancels, of course, leaving:

635 kJ/mol + 393.5 kJ/mol --> 1207 kJmol

Right is more negative than the left so the reaction is exothermic. Calcium carbonate is basically limestone or marble, so a nice building material, mixed with other stuff to stabilize it against acid rain. Leaving the question of where you get the CaO.

Looks like the reactions are all exothermic, but you have to come up with the minerals, which means mining a ton and a bit of rock for every ton of coal you burn. But you get building materials out of the bargain too.

I responded to a misunderstanding of your statement. You don't use carbonates of other metals as a source, you create them. From silicates and CO2. That makes more sense, and silicon is a valuable material in it's own right so I'm sure the waste oxides could be put to good use as silicon ore, just dump it in with the rest of the sand. If it takes an equal mass of ore as CO2 though then things look rather worse than you suggested above - beca

You're right, I should have said 1 ton of mineral per ton of C02. A ton of burned fossil fuel should become about 3.7 tons of C02.

It wouldn't be much fun, but it would still be energetically positive, at least for a little while. If the products are valuable enough zero carbon coal power plants might even be economically competitive with renewables in some places.

A bit of digging finds that they are reacting Olivine (Magnesium silicate) with CO2 giving Magnesium Carbonate.

This reaction has been studied for years as a sequestration reaction for CO2 but traditionally it needs high pressure and moderate temperature to get reasonableconversion of the Olivine. The team at Newcastle Uni have come up with a method to produce Magnesium Carbonate (Dolomite) at much more modest reaction conditions.

I did a bit of digging too but came up empty, or at least everything I found relating to carbonate (my guess as to the material the bricks might be made of) didn't seem to link back to the stakeholders mentioned in TFA so I couldn't be sure. Do you have a link?

A bit of digging finds that they are reacting Olivine (Magnesium silicate) with CO2 giving Magnesium Carbonate.

This reaction has been studied for years as a sequestration reaction for CO2 but traditionally it needs high pressure and moderate temperature to get reasonableconversion of the Olivine. The team at Newcastle Uni have come up with a method to produce Magnesium Carbonate (Dolomite) at much more modest reaction conditions.

So how much CO2 is being produced with this process per ton of CO2 sequestered? There is hardly any point in an exercise like this if the ratio isn't smaller than one.

As was implicitly discussed in a branch above, using limestone is inherently non-viable. You're starting with calcium carbonate, breaking off the carbonate to produce lime, which then gradually converts back into calcium carbonate, so the net carbon absorbed would be zero even in the ideal case. If you produced calcium bicarbonate instead then you'd be grabbing a little extra carbon, but calcium bicarbonate is not known to exist in solid state, so isn't terribly useful.

It won't be that since the raw material to do it would be originally from limestone so entirely pointless and a net carbon gain. I've heard a bit about this research a few years ago but can't remember the details but it wasn't anything so obviously silly - looks like it's time for both of both of us to read the article:)

This sounds similar to an old story I read not too long ago. They had a form of concrete that would absorb CO2, with plans to use that for paving stones or other uses. This new idea sounds like it's being used to make the paving stones directly.

No it doesn't. But if you've got the equipment in place to capture CO2 emissions, then you've probably also got the equipment to separate out much of the other stuff before it gets to your CO2 scrubber and gums up the works, which makes sequestering those other emissions far more viable. Not an ideal solution, but better than today.

The only reason the CO2 is sequestered is because of a particular chemical reaction, which has zero bearing on heavy metals, sulfur compounds, radioactives & other pollutants. One piece of equipment does one job, because each reaction needs its own reactants, catalysts, and general environment, and each has its cost & energy tradeoffs. One particular CO2 reaction has nothing at all to do with the other emissions.

No argument. I'm not suggesting that the CO2 scrubbers magically remove other exhaust components. Just that if you pump a bunch of sooty coal smoke through a CO2 scrubber you will likely get lots on incidental deposits that interfere with it's operation, much like creosote in a stovepipe. Therefore there would be incentive to filter out as much crud as possible before passing through the scrubbers just to keep them working efficiently. And once separated from the exhaust the filtered crud could then be e

The big fossil fuel companies will surely be fans - if say 20% of your produced energy goes to sequestering carbon, then that means you need (20%/80%)= 25% more fuel to produce the same amount of net energy, which equals 25% more profits for them.

The power-generating companies may not like it, since it means 25% higher fuel expenses, plus operating costs for the sequestering plant. If they can make a net profit selling bricks then they may actually be in fav

Looks like the "company" which developed the technology is backed by the University of New South Wales. That's not an institution that normally backs vapour-ware. Typically these are attempts to monetise research and as such typically result in at least pilot trials.

Given the Ample selection of carbonate minerals [wikipedia.org], I don't doubt that you can get an equivalent-to-concrete-or-better construction brick out of a process designed to scrub substantial amounts of otherwise freed carbon dioxide. It will be interesting to see, though, how the whole process stacks up once you factor in the sources of whatever other materials will be reacting with the carbon dioxide.

It's less a question of whether it works, this isn't some 'run your car from water! Secrets Big Oil doesn't want

A ban would make sense except for that Australia has no nuclear powered electricity generation [wikipedia.org]. Even though the country sits on a third of the world's uranium deposits, Australia seems determined politically to wait out the usefulness of uranium until thorium becomes more standard or even fusion becomes possible. Australia is set to possibly become the biggest exporter in the world [australiancoal.com.au] in the future, so politicians desperately hope there is a way to make coal "clean" at little extra cost.

From the US DOE :
"Direct mineral carbonation has been investigated as a process to convert gaseous CO2 into a geologically
stable, solid final form. The process utilizes a solution of sodium bicarbonate (NaHCO3), sodium chloride
(NaCl), and water, mixed with a mineral reactant, such as olivine (Mg 2SiO4) or serpentine [Mg 3Si 2O 5(OH)4].
Carbon dioxide is dissolved into this slurry, by diffusion through the surface and gas dispersion within the
aqueous phase. The process includes dissolution of the minera

CO2 is carbon at its maximum oxydation level (you cannot burn it anymore). Limestone is made of calcium carbonate (and magnesium carbonate in a lesser extent), it is also carbon at its maximum oxydation level. The transformation seems smart, but it requires water (easy part) and calcium. Where will that calcium come from? The usual source is limestone...

CO2 is a problem. PFC are worse. It is not a good idea to burn CO2 further into CF4, if that was your idea.

Oh, definitely not, I try to stay away from large-scale reactions involving fluorine whenever possible. I was just going for cheap 'funny' points (which really makes no sense, since those aren't worth anything, even karma which isn't worth much of anything; and yet I do it anyway...) and expressing my respect for a chemical that can oxidize all sorts of materials that you think of as already about as oxidized as they get.

You can't help but love something that responds to your attempts to extinguish the f

my respect for a chemical that can oxidize all sorts of materials that you think of as already about as oxidized as they get

But if you turn CO2 into CF4, the carbon atom oxidation level does not change. You probably oxidize oxygen in that reaction. Our imagination is without limit, therefore we could dream of oxidizing further by stealing the orbital 1s electrons of the carbon atom, but I am not sure it can ever happen in a chemical reaction with fluorine. Even fluoride has its limits:-)

Why not propane?
They could cart the CO2 and some water to a place with lots of wind or solar but inconvenient access to a hungry power grid and use the Fischer-Tropsch process [wikipedia.org] to synthesize "carbon neutral" ish propane. When it burns, they could recapture the CO2 and do it again.

They could cart the CO2 and some water to a place with lots of wind or solar but inconvenient access to a hungry power grid and use the Fischer-Tropsch process [wikipedia.org] to synthesize "carbon neutral" ish propane. When it burns, they could recapture the CO2 and do it again.

That process looks like it mainly deals with Carbon-Monoxide which is a different animal that Carbon-Dioxide.

Which of course is the definition of not being as easy as other ways that give you lots of the stuff without much effort. In fact it takes so much energy to brute force those bonds that bricks are chicken feed.

You are reminding me of the clown who made fun of chemical efforts to remove carbon dioxide from air. "Just chill it down and the CO2 comes out" said the clown - totally ignoring that everyone else in the discussion had though of that thirty steps ago and were looking for ways to get the same end result with less energy expenditiure. Getting hydrogen from putting electricity in water is like marrying Britney Spears just to get her photograph - you'll get that result but there are many easier ways to do it

I'd expect it to be easier to electrically connect the place than to bring the CO2 there.

Well, unless you could use those bricks as intermediate form. That would make a very compact, transportable substance you could conveniently transport to those propane factories. There the bricks would be split up again to get the CO2 for making propane (or another hydrogenated carbon), and the other substances then brought back to the power plant (together with the fuel) for repeated CO2 capture.

It wouldn't be impossible, but sometimes inconvenient is a big obstacle. Also, wind and solar don't necessarily have peak supply during times of peak demand. If you build extra capacity into the wind and solar equipment so that you have enough extra during peak supply to store some up, making propane could be a storage method - not necessarily the most efficient one, but one that also does something with that CO2 and reduces demand for hydrocarbons out of the ground.

Want to capture and sequester CO2 without all that hubbub and with existing machinery and technology? Plant fast growing pines and forests, cut them down and build houses with them. Wait... we're already doing that. That's CO2 that is sequestered in a building for decades or more. How many tons of wood does a house use? I think figuring out how to properly dispose of bulldozed homes would be a better effort. Such as converting the wood to char and spreading that out on our farmlands where it will remain as

I bet you could get a lot of investors on board with a plan to use solar power to convert atmospheric CO2 into building materials. Just don't tell them that the super-secret device that does so is called a "tree."

Well modded! Lignin or lignen is a complex chemical compound most commonly derived from wood, and an integral part of the secondary cell walls of plants[1] and some algae.[2] The term was introduced in 1819 by de Candolle and is derived from the Latin word lignum,[3] meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose, employing 30% of non-fossil organic carbon,[4] and constituting from a quarter to a third of the dry mass of wood.

Centuries may seem like a long time to you. Just like it did to people a few centuries ago, for whom "not until the 21st century" might as well have been "forever". But it's not really very long. Especially compared to this technology, which can store it stably for millions of years.

There are apparently 2 Australian companies that trap C02 as a brick/solid form.

One being Timbercrete, which takes sawdust and combines it with a variety of things to produce "bricks":http://www.timbercrete.com.au/pdfs/Timbercrete%20an%20Introduction%205_0%20WEB.pdf

The 2nd, being the one that is referenced in this Slashdot post is similar to the techniques used by some of the geothermal power plants where the CO2 bearing waste heat/steam is pumped into Basalt caverns where the acidic mixture results in some

I have a patent pending system that captures carbon from the atmosphere and turns it into wood, for the construction industry. The process only requires water and sunlight, while maintenance costs are minimal.

Really... so we stuff CO2 in the ground, under the sea, in bricks, whatever; how long before it comes back? It's not like it will disappear, it will still be there. So will it pop back up when the buildings bricked with the stuff are demolished? Will the CO2 get re-released from the earth/sea in one, two, or X years? Isn't the whole carbon capture just a way of deferring consequences, passing them off to some future generation?

Sooner of later, regardless of what we do, we will have to grapple with the

First, solid carbon doesn't just magically turn into CO2, so taking CO2 out of the air, ripping of the carbon and making it into solid forms is probably a better way to sequester it then other techniques. Even if you destroy the building, the bricks are not going to release back all its trapped carbon as CO2. Even if the bricks are in a fire they may not release as much CO2 as wood framed building.

Also sequestering IS a great solution because future generations WILL find ways of

The article says they have spent 6 years researching the technology. 6 years ago is also when German researchers published their discovery: http://en.wikipedia.org/wiki/Hydrothermal_carbonization [wikipedia.org] (The German version of the Wikipedia article is much more informative.)

As far as I know, it started with a researcher wondering how exactly the Earth produced coal and oil and discovering that for almost a century nobody had done any new experiments. So he did some, adding some of today's knowledge.

It turns out that if you put water and basically arbitrary organic waste (wood, grass cuttings, leaves, entire weeds, whatever) into a pressure cooker, add some citric acid as a catalyser and then heat it to 200 degrees Celsius, then you get an exothermic reaction which makes the stuff keep that temperature without further input of energy. Provided you are not using an ordinary pressure cooker (which will explode) but some special thingy.

You stop the reaction after 8-12 hours and filtrate the water to get the product. Depending on the precise time you stop, you can create topsoil, oil, brown coal or low-quality stone coal. While the method doesn't seem to produce any excess heat, you can theoretically make an industrialised country CO2 neutral by treating all of its green waste that way and storing the resulting low-quality coal underground, e.g. in an old coal mine.

I mean this is the only real issue with today's use of hydrocarbons, we have not closed the cycle.

Hydrocarbons about one the best forms of energy we have, which is why it is so popular. Its easy to transport, inexpensive to distribute. Consider the impact battery production has on the environment and the fact they pale in comparison to the amount of energy they can store compared to an equivalent volume of hydrocarbons.

The problem is that we have taking carbon reserves from millions of years of oil and na

I just drove from Bathurst to QLD,
And did a little experiment, I would count the number of seconds between dead roos. Highest I got to was 40seconds over a 10minute period. Average was probably 15seconds

TFA shows that the bricks are a light brown. Should go quite well in warm, sunny climates (like... you know Australia!). Although even if they were black, I'm sure they could be painted with a reflective coating.

Are they flammable? The only compressed carbon i know offhand is coal. Nobody will want flammable bricks.

Diamond is another famous form of compressed carbon. These aren't coal or diamonds though. They are a carbon compound. If you stopped to think for a few seconds, you'd realize that they are almost certainly not flammable. High flammability means it has lots of energy stored. This rock is bei

So that was an attempt at a joke of some kind. Ah I see - an imaginary joke out of phase from a real one and relying on a fake "correction" of a real correction. I suppose that could be thought to be funny in a meta sort of way on some sorts of synapse damaging drugs but that's not my field.Your referral to a dictionary after such a deliberate miscommunication certainly reveals a character flaw on your part. My perception of you as a dirty weasel of a liar is reinforced.